A printing service in Palo Alto has refused to release two images it reproduced for a show of political art scheduled to open this week at a San Francisco art gallery, saying they violated company policy against depicting torture and the disparagement of religion.

The printing service, called Zazzle, informed artist Clinton Fein on Monday that it would not release two of six images for "Numb & Number," an exhibit of Fein's deliberately provocative political art scheduled to open this evening at the Toomey Tourell Gallery at 49 Geary St.

The first of the two images is of an American flag with the now infamous hooded figure of an Abu Ghurayb prisoner substituted for the stars. The second features President Bush's face superimposed on Jesus' on the cross. Over the Christ figure are the words, "Who Would Jesus Torture?'' and, "From the Industrial Moral Military God Complex.'' That image also contains a missile positioned as a phallus.

Matt Wilsey, director of business development for Zazzle, said the company's guidelines, which are posted on its Web site (www.zazzle.com), prohibit depictions of "excessive violence" and "derogatory references about religion'' among other restrictions. Zazzle's primary business is to print and sell reproductions on the Internet. It allows customers to post their images there for resale and a small commission.

Wilsey acknowledged that the guidelines are primarily intended for those who publish images on the Zazzle Web site, but said they also apply to cases like Fein's where the customer is using Zazzle exclusively as a private printing service. He said being associated with images such as Fein's is at odds with the image the company wants to project and that it was not obligated to print them.

But Fein has cried censorship and speculated that the printer doesn't want to offend the Hoover Institution, a conservative think tank located at Stanford and a major partner of Zazzle, which publishes posters from the Hoover collection via the firm's Web site. He said the public never would have known who had done the printing had they not made an issue of it.

Even if another printer can complete work on the withheld images in time for the opening, Fein said, the work probably wouldn't look exactly like the work Zazzle did. He said he intended to post a notice on the gallery wall to explain what happened.

Fein, a native of South Africa who has said he moved to the United States for its protections of free speech, is no stranger to censorship controversies. It was Fein who created Annoy.com, a provocative political Web site, in response to the passage of the 1997 Communications Decency Act, which made it illegal to send communications over the Internet that are "indecent" with "intent to annoy."

Fein lost a subsequent bid to overturn the act by suing then-Attorney General Janet Reno, but the suit did manage to get the statute redefined so that offensive and annoying communications remain a form of protected speech online.

"I know this stuff is in your face,'' Fein said. "That's the point. My philosophy is you need to stir people from apathy. In my opinion, political statements in art should not be sugar-coated."